Detection of the difference in phase between two electrical signals is a function that is of interest in a great many fields within electrical engineering. Radio, television, radar and mobile telephony may be mentioned among the many possible areas of application of detection of phase difference.
As detection of phase difference, also known as phase detection, has such a great many areas of application, there is a great interest in developing methods and arrangements that make possible inexpensive, operationally reliable and unambiguous phase detection. A problem in this respect is that the frequency ranges in which it is desirable to use phase detectors are increasing constantly. It is of course highly desirable, in higher frequency ranges also, to be able to carry out unambiguous phase detection within an angular interval of 360.degree.. At present, however, there are few phase detectors that, within higher frequency ranges and above all the microwave range, satisfy the abovementioned requirement for inexpensive, operationally reliable and unambiguous phase detection within a full angular interval of 360.degree.; most phase detectors allow unambiguous phase detection only within an angular interval of 180.degree..
Among known methods and arrangements for solving the abovementioned problems concerning phase detection, mention may be made of those that are described in EP 379 321, EP 256 637 and U.S. Pat. No. 5,552,750.
However, all these documents disclose solutions that are based on digital technology, which may be said to provide expensive and complex solutions.